1. Field of the Invention
The present invention relates generally to manual actuating apparatus for operating a medical device and, more specifically, to such apparatus constructed to assure a comfortable hand posture for the operator throughout the complete range of operation of the medical device. The medical device may be, for example, a multifunctional minimally invasive surgical instrument.
2. Description of the Prior Art
Minimally invasive surgical procedures are being used with increasing regularity. These procedures are performed with minimally invasive surgical instruments which include a tool on the end of an elongated support tube opposite a handle. Access to the surgical site is provided by a trocar which is used to puncture and insert a cannula or hollow tube through the patient's skin and muscle tissue. The tool of the surgical instrument is positioned at the surgical site after being inserted through the cannula. The surgeon then manipulates a lever or other actuator on the handle to perform the surgical operation. This procedure is carried out while viewing the surgical site on a video monitor. Minimally invasive surgical procedures of this type offer substantial benefits to the patient in terms of reduced post-operative pain, reduced recovery time, and lower cost.
In a variety of medical devices used for a diversity of surgical or non-surgical procedures, devices are designed with a dedicated handle or proximal end and a distal or actuation end. Typically medical device handles prescribe how they will be held in the hand by the layout of their handle shape or position of finger loops. In instruments that contain loops, such as can be found in scissors type devices or grasping type devices, the loops are used for opening and closing the end effector, whether that is a scissors, grasper, clamp or similar device. In medical devices and more specifically minimally invasive or laparoscopic devices, a wide variety of angles of use can be generated. Typically a finger-looped device locks the fingers and hand into a single orientation that can only function comfortably across a limited range of angles. Both in angles distal or away from the user and oblique angles or angles acutely to the side of the user, devices with finger loops move beyond their effective comfort range and promote hand stress and fatigue. This stress and discomfort is the result of creating unnatural hand postures. These hand postures can create severe wrist adduction or flexion causing discomfort and a loss of strength or leverage to operate the device. In certain instruments such as instruments used for minimally invasive or laparoscopic dissection, a surgeon may operate a looped device for long periods of time, across a wide range of angles.
In most instances known to the inventor, when a handle for operating a medical device employs three or more finger or thumb elements, those elements in excess of the standard two for performing a certain function serve a different function. Typical examples of the prior art can be found in U.S. Pat. No. 6,299,625 to Bacher, No. 6,258,101 to Blake, III, No. 6,066,146 to Carroll et al., No. 5,456,684, and No. 5,376,094 to Kline. The noted condition for handles having multiple finger and thumb elements exists in each of these patented constructions.
It was with knowledge of the foregoing state of the technology that the present invention has been conceived.